Air filter control apparatus for controlling movement of filter medium through a gas-treating section



March 28, 1967 REVELL 3,310,931 AIR FILTER CONTROL APPARATUS FOR CONTROLLING MOVEMENT 0F FILTER MEDIUM THROUGH A GAS-TREATING SECTION Filed July 1, 1965 INVENTOR.

ALAN E. REVELL ATTORNEY United States Patent 3,310,931 AIR FILTER CONTROL APPARATUS FOR CON- TROLLING MOVEMENT 0F FILTER MEDIUM THROUGH A GAS-TREATING SECTION Alan E. Revel], Louisville, Ky., assignor to American Air Filter Company, Inc., Louisville, Ky., a corporation of Delaware Filed July 1, 1963, Ser. No. 291,724 4 Claims. (Cl. 55-354) This invention relates to automatic air filters of the type wherein filter material is advanced from a supply zone through an air filter zone to a rewind zone and more particularly this invention relates to an improved control apparatus for advancing the filter material in such automatic air filters.

In accordance with the present invention, a novel switch and metering arrangement for filter material control apparatus is provided which can be readily and accurately installed in an automatic air filter in a straightforward manner, the structure of the present invention requiring a minimum of parts to improve the overall efficiency in assembly and maintenance operations. Further, the switch and metering arrangement of the present invention provides accurate filter material control notwithstanding some tolerance variations in the overall structure with which it is assembled.

Various other features of the present invention will become obvious to one skilled in :the art upon reading the disclosure set forth herein.

More particularly the present invention provides: in a web advance control system for air filter apparatus wherein advance of a web of filter material in a filter housing from a supply zone through an air filtering zone to a rewind zone is affected by rewinding the material on a rewind spool driven by a motor in a power circuit including switch means cooperating with a metering means responsive to movement of the filter material, an improved switch and metering means arrangement comprising: a metering reel shaft responsive to movement of the filter material and having a cam member position at one end thereof; a channel or U-shaped bracket member hav ing a plunger-responsive switch mounted between :the sides thereof; an actuator arm pivotally mounted between the sides of the U-shaped bracket to operate the plungerresponsive switch; and slot means in the sides of the U- shaped bracket .at one end thereof and adjacent an extremity of the actuator arm whereby the U-shaped bracket can be positioned to engage the metering reel shaft to span the cam member with an extremity of the actuator arm positioned immediately below the cam member and the pivot axis of the actuator arm always at a fixed preselected distance from the axis of the metering reel shaft to assure accurately sequenced actuation of the plungerresponsive switch through the cam member and actuator arm.

It is to be understood that various changes can be made by one skilled in the art in the arrangement, form, and construction of the apparatus disclosed herein without departing from the scope or spirit of the present invention.

Referring to the drawing which discloses one advantageous embodiment of the present invention:

FIGURE 1 is an elevational isometric view of an automatic air filter in which the inventive apparatus is incorporated;

FIGURE 2 is an enlarged, partially broken away view of the upper portion of the air filter of FIGURE 1, disclosing a portion of the inventive filter material control apparatus;

FIGURE 3 is an enlarged isometric view of a switch I 3,31%,931 Patented Mar. 28, 1967 structure adapted to be assembled with the control apparatus of FIGURE 2;

FIGURE 4 is an enlarged partially broken away side elevational view of the apparatus of FIGURE 2 taken in a plane passing through line 44 of FIGURE 1 disclosing the switch structure of FIGURE 3 in assembled position; and

FIGURE 5 is an enlarged exploded view of a telescopic fitting employed with the switch structure of FIGURE 3.

Referring to FIGURE 1 of the drawing, filter housing 2 for an automatic roll-type air filter is disclosed in vertical position. Housing 2 includes upper filter material supply zone 3, central air filtering zone 4 and lower filter material rewind zone 6. Mounted in tightly wound form in supply zone 3 is a supply roll of filter material 7. Roll 7 can be comprised of any one of a number of known filter materials. For example, a material such as expansible-compressible fiber glass can be utilized. As is known in the art, a web of filter material 8 from roll 7 is advanced incrementally from time-to-time into and through the central air filtering zone 4 which zone includes housing structure that frames the air stream passage through whieh the air to be treated must flow. As the web of filter material 8 is progressively advanced through central air filtering zone 4, the web assumes an expanded thickness or comparatively three dimensional proportion to filter contaminants from the air stream. The web 8 is then correspondingly progressively advanced to the rewind zone 6 where it is tightly wound upon rewind spool 9 driven by a suitable drive motor broadly designated by reference numeral 10. Motor 10, which is part of the power circuit that includes the switch and metering means assembly of FIGURES 2-4, is not disclosed in detail herein. It is to be understood that the present invention can be incorporated as part of any one of a number of known power circuits, the wiring portion of which is not disclosed :herein. Advantageously, a power circuit similar to that disclosed in assignees Patent No. 3,020,976, issued to P. L. Hyatt on Feb. 13, 1962, can be utilized. Since the specific wiring of the power circuit does not constitute an essential part of the present invention, details thereof are not disclosed herein.

Referring to FIGURES 2 and 3 of the drawing, the switch and metering assembly is disclosed as including a metering reel 11 rotatably mounted in supply zone 3 in a suitable form of journal box arrangement (not shown). Web 8 is arranged to pass over metering reel 11 before the web enters into the central air filtering zone 4, the web rotating the reel as it is moved downwardly. Reel 11 has a cam 15 mounted at one end thereof, the reel shaft passing through plate member 12 fixed to filter housing 2. It is to be noted that plate member 12 is provided with slot 13 along one edge thereof, slot 13 being suitably positioned to be in preselected alignment with an aperture 27 in housing 2 and to receive a stop-pin 14 of switch assembly 16 described in detail hereinafter.

As can be seen in FIGURE 3, switch assembly 16 includes a channel or U-shaped bracket member 17 having a plunger-responsive switch 18 mounted between the sides and at one end thereof. A conduit 19, which along with its telescopic fittings, as will be seen hereinafter, is carefully sized to insure a locking arrangement of the switch and metering means assembly in housing 2, is provided at one end of a threaded nipple on switch 18 to carry switch wires which connect switch 18 into the power circuit that includes motor 10. It is to be noted that conduit 19 is connected to the switch through a telescopic fitting arrangement such as disclosed in FIGURE 5. This telescopic fitting arrangement includes a threaded union member 20, a split clamping ring 21 and a draw-down nut 22. It is to be further noted that a similar telescopic fitting arrangement is provided at the opposite end of conduit 19 for reasons described hereinafter.

Pivotally mounted between the sides of bracket member 17 on pivot pin 23 is switch actuator arm 24. The pivot pin 23 is so positioned in bracket member 17 that, when the overall structure is assembled with metering reel 11, one end of actuator arm 24 engages plunger-responsive switch 18 as the other end of the actuator arm is engaged by cam 15. It is to be noted that U-shaped bracket member 17 is provided with a pair of slots 26 at that end opposite the end which carries switch 18. Further, bracket member 17 carries the aforedescribed stop-pin 14 which projects outwardly from one side thereof.

In a typical assembly operation of the switch and metering reel into housing 2, slots 26 at one end of bracket member 17 are positioned to engage metering reel shaft 11 so as to span cam 15, an extremity of switch actuator arm 24 falling immediately below cam 15. Thus, the pivot axis 23 of actuator arm 24 is fixed at a preselected distance from the rotational axis of metering reel shaft 11. This assures an accurate sequencing of the plunger-responsive switch 18 mounted at the other end of bracket 17 through the cam and actuator arm regardless of tolerance variations which might exist in each of the several parts assembled together. When slots 26 of bracket 17 have engaged metering reel shaft 11, the switch assembly 16 is rotated about shaft 11 until stoppin 14 projecting from the side of bracket 17 engages into slot 13 of plate member 12 fixed to filter housing 2. This stops rotational movement of the switch assembly. Conduit 19, along with telescopic fittings 20, 21, 22 at its extremities, are then adjusted so that the extremity of the conduit opposite that extremiy which is fastened to switch assembly 16 is fastened to extend through aperture 27 in housing 2. As will be noted, conduit 19 is sized and aperture 27 in housing 2 is so positioned in relation with slot 13, that pin 14 is held fast in slot 13 and a locking arrangement of the switch and metering means assembly is effected in housing 2.

From the above description, it can be readily seen that the novel switch and metering assembly can be installed in a straightforward manner, requiring a minimum of parts yet assuring accurate filter material control notwithstanding any tolerance variations which might exist in the several parts of the overall structure.

The invention claimed is:

1. In a web advance control system for air filter apparatus wherein advance of a web of filter material in a filter housing from a supply zone through an air filtering zone to a rewind zone is efiected by rewinding said material on a rewind spool driven by a motor in a power circuit including switch means cooperating with metering means responsive to movement of the filter material, an improved switch and metering arrangement comprising:

(a) a metering reel shaft means constructed and arranged in said filter housing for responding to the movement of said filter material and having a cam member positioned at one end thereof;

(b) a U-shaped bracket having a plunger-responsive switch mounted between the sides thereof;

(c) an actuator arm means pivotally mounted between the sides of said Ushaped bracket for cooperating with said plunger-responsive switch;

(d) open-end slot means in the sides of said U-shaped bracket extending to the edges thereof at one end thereof and adjacent an extremity of said actuator arm for positioning said bracket to engage said metering reel shaft and for spanning said cam with an extremity of said actuator arm immediately below saidcam so that the pivot axis of said actuator arm is always at a fixed preselected distance from the rotational axis of said metering reel shaft to assure accurately sequenced actuation of said switch through said cam and said actuator arm; and

(e) means to position said bracket in a preselected position relative said filter housing after it has engaged said metering reel shaft, said means including a stop-pin member fixed to a side of said U-shaped bracket and a plate member fixed to said filter housing, said plate member having a slot therein positioned to receive said pin member.

2. The apparatus of claim 1, said positioning means further including a telescopic conduit assembly connectable at one end to said U-shaped bracket and sized to be telescopically connectable at the other end to said filter housing after said pin member has engaged in said slot of said fixed plate member.

3. In a web advance control system for air filter appa ratus wherein advance of a web of filter material in a filter housing from a supply zone through an air filtering zone to a rewind spool is effected by rewinding said material on a rewind spool driven by a motor in a power circuit including switch means cooperating with metering means responsive to movement of the filter material, an improved switch and metering means arrangement comprising:

(a) a metering reel shaft rotatably mounted in said supply zone of said filter housing to be rotationally responsive to movement of said filter material which passes thereover;

(b) a cam member positioned at one extremity of said metering reel shaft to rotate therewith;

(c) a U-shaped bracket having a plunger-responsive switch mounted between the sides of said bracket at one extremity thereof;

(d) a switch actuator arm pivotally mounted about a pivot axis extending between the sides of said U-shaped bracket so that one extremity can cooperate with said plunger-responsive switch;

(e) a pair of slots in the side of said U-shaped bracket at the extremity opposite that extremity in which said switch is mounted and adjacent the other extremity of said actuator arm whereby said bracket can be positioned to engage said metering reel shaft and span said cam with an extremity of said actuator arm immediately below said cam and the pivot axis of said actuator arm always at a fixed preselected distance from the rotational axis of said metering reel shaft to assure accurately sequenced actuation of said switch through said cam and said actuator arm;

(f) a stop-pin member fixed to a side of said U-shaped bracket above said pivot axis of said actuator arm;

(g) a plate member fixed to said filter housing;

(h) a slot in said plate member adapted to receive said stop-pin member of said U-shaped bracket;

(i) an aperture in the supply zone of said housing;

and,

(j) a telescopic conduit assembly connectable at one end to said U-shaped bracket and sized to be telescopically connectable at the other end through said aperture in said filter housing after said stop-pin member has engaged in said slot of said fixed plate member.

4. The apparatus of claim 3, said telescopic conduit assembly comprising a preselected sized conduit and a fitting assembly at each end thereof including a union, a clamping ring and draw-down nut.

References Cited by the Examiner UNITED STATES PATENTS 1,742,779 1/1930 Nutt 74-53 2,181,829 11/1939 Jeffrey. 2,454,341 11/ 1948 Repka. 2,511,271 6/1950 Kaminky et al. 2,648,234 8/1953 Lester. 2,771,251 ll/1956 Silverstein.

(Other references on following page) 5 6 UNITED STATES PATENTS 3,102,014 8/1963 Aitkenhead 55-271 1 55 271 3,115,999 12/1963 Wythe 226-33 X 3,182,146 5/1965 Levpold. Marturano 21161.14 X FOREIGN PATENTS g 729,207 4/1932 France. 1,260,113 3/1961 France. Aqulllon. Cawthon et a1 55-452 FRANK W. LUTTER, Primary Examiner. Pfarrwaller 7453 X c 200 1 13 X 19 HARRY B. THORNTON, Examiner.

Palmore 55-254 X D. TALBERT, Assistant Examiner. Martin 33132 X 

1. IN A WEB ADVANCE CONTROL SYSTEM FOR AIR FILTER APPARATUS WHEREIN ADVANCE OF A WEB OF FILTER MATERIAL IN A FILTER HOUSING FROM A SUPPLY ZONE THROUGH AN AIR FILTERING ZONE TO A REWIND ZONE IS EFFECTED BY REWINDING SAID MATERIAL ON A REWIND SPOOL DRIVEN BY A MOTOR IN A POWER CIRCUIT INCLUDING SWITCH MEANS COOPERATING WITH METERING MEANS RESPONSIVE TO MOVEMENT OF THE FILTER MATERIAL, AN IMPROVED SWITCH AND METERING ARRANGEMENT COMPRISING: (A) A METERING REEL SHAFT MEANS CONSTRUCTED AND ARRANGED IN SAID FILTER HOUSING FOR RESPONDING TO THE MOVEMENT OF SAID FILTER MATERIAL AND HAVING A CAM MEMBER POSITIONED AT ONE END THEREOF; (B) A U-SHAPED BRACKET HAVING A PLUNGER-RESPONSIVE SWITCH MOUNTED BETWEEN THE SIDES THEREOF; (C) AN ACTUATOR ARM MEANS PIVOTALLY MOUNTED BETWEEN THE SIDES OF SAID U-SHAPED BRACKET FOR COOPERATING WITH SAID PLUNGER-RESPONSIVE SWITCH; (D) OPEN-END SLOT MEANS IN THE SIDES OF SAID U-SHAPED BRACKET EXTENDING TO THE EDGES THEREOF AT ONE END THEREOF AND ADJACENT AN EXTREMITY OF SAID ACTUATOR ARM FOR POSITIONING SAID BRACKET TO ENGAGE SAID METERING REEL SHAFT AND FOR SPANNING SAID CAM WITH AN EXTREMITY OF SAID ACTUATOR ARM IMMEDIATELY BELOW SAID CAM SO THAT THE PIVOT AXIS OF SAID ACTUATOR ARM IS ALWAYS AT A FIXED PRESELECTED DISTANCE FROM THE ROTATIONAL AXIS OF SAID METERING REEL SHAFT TO ASSURE ACCURATELY SEQUENCED ACTUATION OF SAID SWITCH THROUGH SAID CAM AND SAID ACTUATOR ARM; AND (E) MEANS TO POSITION SAID BRACKET IN A PRESELECTED POSITION RELATIVE SAID FILTER HOUSING AFTER IT HAS ENGAGED SAID METERING REEL SHAFT, SAID MEANS INCLUDING A STOP-PIN MEMBER FIXED TO A SIDE OF SAID U-SHAPED BRACKET AND A PLATE MEMBER FIXED TO SAID FILTER HOUSING, SAID PLATE MEMBER HAVING A SLOT THEREIN POSITIONED TO RECEIVE SAID PIN MEMBER. 